using System;
using iTextSharp.text;
using iTextSharp.text.pdf;
using iTextSharp.text.error_messages;
/*
 * $Id: JBIG2Image.cs 106 2009-12-07 12:23:50Z psoares33 $
 *
 * This file is part of the iText project.
 * Copyright (c) 1998-2009 1T3XT BVBA
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * you must retain the producer line in every PDF that is created or manipulated
 * using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */

namespace iTextSharp.text.pdf.codec {

    /**
    * Support for JBIG2 Images.
    * This class assumes that we are always embedding into a pdf.
    * 
    * @since 2.1.5
    */
    public class JBIG2Image {

        /**
        * Gets a byte array that can be used as a /JBIG2Globals,
        * or null if not applicable to the given jbig2.
        * @param   ra  an random access file or array
        * @return  a byte array
        */
        public static byte[] GetGlobalSegment(RandomAccessFileOrArray ra ) {
            try {
                JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
                sr.Read();
                return sr.GetGlobal(true);
            } catch {
                return null;
            }
        }
        
        /**
        * returns an Image representing the given page.
        * @param ra    the file or array containing the image
        * @param page  the page number of the image
        * @return  an Image object
        */
        public static Image GetJbig2Image(RandomAccessFileOrArray ra, int page) {
            if (page < 1)
                throw new ArgumentException(MessageLocalization.GetComposedMessage("the.page.number.must.be.gt.eq.1"));
            
            JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
            sr.Read();
            JBIG2SegmentReader.JBIG2Page p = sr.GetPage(page);
            Image img = new ImgJBIG2(p.pageBitmapWidth, p.pageBitmapHeight, p.GetData(true), sr.GetGlobal(true));
            return img;
        }

        /***
        * Gets the number of pages in a JBIG2 image.
        * @param ra    a random acces file array containing a JBIG2 image
        * @return  the number of pages
        */
        public static int GetNumberOfPages(RandomAccessFileOrArray ra) {
            JBIG2SegmentReader sr = new JBIG2SegmentReader(ra);
            sr.Read();
            return sr.NumberOfPages();
        }
    }
}
